Iron(II) selenate - Misplaced Pages

Iron(II) selenate
Names
Other names Ferrous selenate
Identifiers
CAS Number	(anhydrous): 15857-43-9 (pentahydrate): 70807-08-8
3D model (JSmol)	(anhydrous): Interactive image (pentahydrate): Interactive image
PubChem CID	(anhydrous): 159739849
InChI (anhydrous): InChI=1S/Fe.H2O4Se/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2Key: NCHUFZYUFAWBQI-UHFFFAOYSA-L (pentahydrate): InChI=1S/Fe.H2O4Se.5H2O/c;1-5(2,3)4;;;;;/h;(H2,1,2,3,4);5*1H2/q+2;;;;;;/p-2Key: YXLBLVIIVLRXHU-UHFFFAOYSA-L
SMILES (anhydrous): (=O)(=O). (pentahydrate): (=O)(=O)..O.O.O.O.O
Properties
Chemical formula	FeSeO₄
Molar mass	198.8046 g/mol (anhydrous) 288.881 g/mol (pentahydrate) 324.91156 g/mol (heptahydrate)
Appearance	green, unstable crystalline solid (heptahydrate)
Solubility in water	soluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references

Chemical compound

Iron(II) selenate (ferrous selenate) is an inorganic compound with the formula FeSeO₄. It has anhydrous and several hydrate forms. The pentahydrate has the structure, SeO₄•H₂O, isomorphous to the corresponding iron(II) sulfate. Heptahydrate is also known, in form of unstable green crystalline solid.

Preparation

Iron(II) selenate can be prepared by the reaction of saturated sodium selenate and iron(II) sulfate at 80 °C. When cooled to room temperature, crystalline iron(II) selenate precipitates from the solution.

Na₂SeO₄ (sat.) + FeSO₄ → Na₂SO₄ + FeSeO₄

The reaction of iron and selenic acid produces iron(II) selenate as well, but with a side product:

Fe + H₂SeO₄ → FeSeO₄ + H₂↑

3 Fe + 4 H₂SeO₄ → 3 FeSeO₄ + Se + 4 H₂O

Other species containing oxoanion of selenium

Double salts like the Tutton's salts (NH₄)₂Fe(SeO₄)₂•6H₂O and K₂Fe(SeO₄)₂•6H₂O are known.

In addition to the ferrous (Fe) salt, the ferric (Fe) salt iron(III) selenate, Fe₂(SeO₄)₃, has also been reported.

However, iron(II) selenite (FeSeO₃) is unknown, though the selenite and pyroselenite of iron(III) was published.

References

CAS No. from SciFinder
K. Heinzinger, G. Pálinkás, Hubertus Kleeberg. Interactions of Water in Ionic and Nonionic Hydrates: Proceedings of a Symposium in honour of the 65th birthday of W.A.P. Luck Marburg/FRG, 2.–3.4. 1987. Springer-Verlag Berlin Heidelberg, 1987
^ A E H Tutton. Selenic Acid and Iron. - Reduction of Selenic Acid by Nascent Hydrogen and Hydrogen Sulphide. - Preparation of Ferrous Selenate and Double Selenates of Iron Group. Proceedings of the Royal Society A, 1918 , 94 (241) :352-361
Filonenko, E. N.; Vergeichik, E. N.. Preparation and analysis of cobalt (II) selenate and iron (II) selenate. Farmatsiya (Moscow), 1998. 47 (3): 36-37
G Giester, F Pertlik. Synthesis and crystal structure of iron(III) selenate(IV) trihydrate, Fe₂(SeO₃)₃·3H₂O. Journal of Alloys & Compounds, 1994 , 210 (1-2) :125-128
Pinaev, G. F.; Stukan, R. A.; Makarov, E. F.. Moessbauer effect in iron(3+) selenites. Zhurnal Neorganicheskoi Khimii, 1977. 22 (7): 1731-1733